JPS62142606A - Molding equipment for ceramics, etc. - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a molding apparatus used in a process of molding ceramics or the like before a degreasing/firing process.

(Conventional technology) Conventionally, in the production of ceramic products by injection molding, ceramic powder is heated and kneaded with a binder such as a thermoplastic organic material, cooled, and then crushed into pellets, which are then injection molded as raw materials and removed from the mold. Degrease the molded product.
Injection molding uses a molding machine that is almost the same as an injection molding machine for plastics, and uses the same molding principle.

(Problems to be Solved by the Invention) However, injection molding of ceramics is carried out using a molding machine that is almost the same as the injection molding machine for plastics and based on the same molding principle. As shown, the molten material forms a string having the thickness of the gate 20 and is filled into the cavity 21 in a folded manner. In addition, injection pressure is applied in this state, but the pressure is transmitted to the sprue runner 22.
Since this is carried out through the gate 20, the pressure drop is large and it is difficult to obtain a high pressure and uniform pressure distribution within the cavity 21. Therefore, the precision of the molded product is not good and the molded product is degreased.

There is a disadvantage that the molded product is easily chipped or cracked at the boundary surface during the firing process.

Therefore, as a measure to eliminate this inconvenience, it may be possible to increase the diameter of the sprue in order to make the pressure distribution inside the cavity 21 uniform, but in this case, the volume of the wasted part other than the product will increase, and the yield will decrease. becomes worse. Also,
For example, conventional injection molding machines cannot adequately handle thick-walled molded products or molded products that cause welds.

The present invention was devised to solve the above-mentioned conventional problems, and an object of the present invention is to make it possible to mold a high-quality molded product with a high yield and a small number of boundary surfaces inside the molded product.

(Means for Solving the Problems) In the apparatus for molding ceramics, etc. of the present invention, a fixed side mold mounted on a fixed platen is provided with a through hole passing through the mold, and a movable side mold is provided in the through hole. A plunger that can move back and forth toward the side of the mold is inserted, and a wall boat that opens and closes as the plunger moves back and forth is provided on the side wall of the through hole, and the wall boat can melt, measure, and inject the material. It is characterized by connecting the molten material injection passage of the plasticizing device.
With this configuration, after the injected molten material is temporarily stored in the through hole (pressure chamber), this lumpy material can be pressurized with a plunger and filled into the cavity, and the molded product is formed by the high-pressure filling that causes plastic deformation. This makes it possible to reduce internal boundary surfaces and improve the precision of the molded product.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

In the figure, l denotes a stationary mold, which is attached to the stationary platen 2. Reference numeral 3 denotes a movable side mold, which is attached to a movable platen 4, and is connected to a clamping device 5 (a cylinder in the embodiment) by a tie bar.
6, it can move forward and backward relative to the fixed mold 3.

A core mold 7 is attached to the tip of an ejector pin 8 of a molded product ejection mechanism provided on the movable platen 4, and is disposed within the movable mold 3.

Reference numeral 9 denotes a plunger, which is inserted into the through hole 1 provided in the fixed side mold unit.
The moving device 1 (in the embodiment, a cylinder) is fitted into the platen 2 so as to be movable back and forth, and is placed facing the tip surface of the core mold 2 and the ejector pin 8, and is provided on the fixed platen 2. They are connected and can be moved forward and backward by the device 1 toward the movable mold 3 side.

A pressure chamber 2 is formed in the through hole 10 just in case the plunger 9 is retracted, and the chamber 2 is filled with the plunger 9 when the plunger 9 advances to the forward end position.

13 is a wall boat with a diameter of 20~301u+, with a through hole 10
It is provided on the wall of the plunger 9 and is opened and closed by moving the plunger 9 back and forth.

14 is a plasticizing device, in which a screw 16 that can be rotated and moved back and forth by a drive device (not shown) is fitted into a barrel 15;
The material from the hopper can be melted, measured, and injected.

A plasticizing device 14 is fixedly disposed on the fixed platen 2 side, and a barrel outlet of the device 14 is formed to have the same diameter as the wall boat 13 and is connected to it.

A cavity 18 is composed of the molds 1 and 3 which are closed by a mold clamping device 5, a core mold 7, and an ejector pin 8.

Reference numeral 19 denotes a passage provided in the fixed mold 1, with one end opening into the through hole 10, and the other end extending to the outside of the mold 1, and connected to a vacuum pump (not shown). The movable mold 3 is clamped to remove air from the pressure chamber 2 and the cavity 18 before injection.

(Operation) Molding using this device is performed in the following steps (2) to (6).

(1) In the plasticizing device 14, a molten material M measured by the amount of retraction of the screw 16 is prepared in the tip of the barrel unit 5 (see Figure 1).

(2) After the molds 1 and 3 are closed by the mold clamping device 5, the plunger 9 is moved back by the drive device 11, thereby forming the pressurizing chamber 12 and opening the wall boat 13.

(3) The screw 16 of the plasticizing device 14 is rapidly advanced, and the molten material M is transferred from the open wall boat 13 to the pressurizing chamber 1.
2 (see Figure 2).

In this case, the outlet of the barrel 15 and the wall port 13 are formed considerably larger than the nozzle diameter (2 to 5H) in a conventional injection molding machine, so high-speed injection is possible.

Note that, prior to injection, if necessary, a vacuum pump (not shown) is operated to remove air from the cavity within one day, thereby preventing molding defects due to air entrapment.

(4) The plunger 10 is advanced by the driving device 11, and the molten material M in the pressurizing chamber 12 is pressurized between the core mold 7, the ejector pin 8, and the plunger 10, and is pushed into the cavity 18 and filled. be done. (See Figure 3).

(5) After the molded body W is solidified by cooling the molds 1 and 3.7 by a temperature control mechanism (not shown), the molds 1 and 3 are opened by the mold clamping device 5, and then the core mold 7 is opened by the molded product ejection mechanism.
Then, the ejector tape/8 is ejected, and the molded body W is taken out from the cavity 18 (see FIG. 4).

(6) While discharging the molded product W, the screw 16 is rotated,
While plasticizing and transporting the material within the barrel 15, the screw 16 is retracted and a certain amount of molten material M is transferred to the barrel 15.
It is stored at the tip and prepared for the next process.

The material in the hopper 17 is ceramic powder 1 by weight.
00 parts to 13 to 2 parts of thermoplastic organic material such as wax
The molded product W, which is the source of ceramic products, is molded by the above molding procedure. If metal powder such as iron, stainless steel, or nickel is used instead of ceramic powder, it becomes possible to mold the molded product that is the basis for metal products.

(Effects of the Invention) As described above, the present invention is capable of high-speed injection and high-pressure filling of the injected molten material into the cavity through pressure molding, so there are almost no boundary surfaces inside the molded product. It can reliably mold high-quality molded products, and is fully compatible with molding of thin-walled molded products, thick-walled molded products, molded products that cause welding, and molding at low temperatures.In addition, it can also be used for molding at low temperatures. Since the distance between the barrels can be shortened and the barrel outlet can be reliably opened and closed with a plunger, there is no material loss and yields are significantly improved.

[Brief explanation of drawings]

FIG. 1, FIG. 2, FIG. 3, and FIG. 4 are schematic diagrams showing one embodiment of the present invention in the order of molding steps. FIG. 5 is an explanatory diagram of the state of filling the inside of the cavity using the conventional device, and the figures <1), (2) l (3) and (4) show the filling process. 1... Fixed side mold, 2... Fixed platen, 3...
Movable side mold, 4... Movable platen, 5... Mold clamping device, 6... Tie bar, 9... Plunger, 10...
Through hole, 11... Drive device, 12... Pressure chamber, 13
... wall surface), -14 ... plasticizing device, 15 ...
・Barrel, Yu 6...Screw, 17...Hopper, 1
8...capity, M...molten material, W...molded product. Figure 5 Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] A through hole is provided in the fixed side mold attached to the fixed platen, and a plunger that can move back and forth toward the movable side mold is fitted into the through hole, and The side wall is provided with a wall port that opens and closes by moving a plunger back and forth, and the wall port is connected to a molten material injection passage of a plasticizing device capable of melting, measuring, and injecting the material. Molding equipment.